> However, the apostrophe inconsistently vanishes in proper names, e.g.Locally, afaik, there's never an apostrophe in "Marthas Vineyard".
> the variation in placenames such as "St Martins" in Salop (Anglice
> 'Shropshire') but "St Martin's" near Perth (the old Scottish capital).
> Omission seems to be the rule in surnames.